Steady-rest.



H. W DUNBAR.

STEADY REST.

APPLICATION FILED AUG. 13. 1917.

1,295,286. Patnted Feb.25,1919.

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HOWARD W. DUNBAR, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO NORTGNGRINDING COMPANY, A CORPORATION OF MASSACHUSETTS.

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Application filed August 13, 1917.

To all whom z'tmay concern:

Be it known that I, HOWARD W. DUNBAR, a citizen of the United States ofAmerica, residing at Vorcester, in the county of Worcester and State ofMassachusetts, have invented certain new and useful Improvements inSteady-Rests, of which the followin is a full, clear, and exactspecification.

y invention relates to work supports and more particularly to steadyrests .for sup porting rotating work whose surface is being ground,turned or otherwise formed into a cylindrical shape.

In the art of forming cylindrical surfaces, such as pins or bearings forcrankshafts, it is often necessary to support the rotating work againstthe action of gravity and the pressure of the grinding wheel or otherforming tool and to overcome the various detrimental effects due towarping, sagging. vibration or an out of balance condition of the work.Since grinding-5s well as other similar operations, to be duplicated,muts be carried on with a fine degree of accuracy, great care isnecessary to move a steady rest back and forth to allow replacement ofthe work and to position the rest correctly with referen'ce'to the work;hence a fine motion derice is necessary for such adjustments. Many typesof work such as that of grinding crankshafts require not only fineadjustments but frequent changing of the article being treated; hence,in such cases involving a large number of short successive grindingoperations, there results a considerable waste of the operators time ifhe is obliged "to move the steady rest toward and from the work by meansof the slowly actuated mechanism heretofore provided for that purpose.

It is accordingly an object of my invention to provide a simple, easilyactuated steady rest, capable of supporting work correctly, with fineprecision means for ad sting the rest into exact relation to the work,and with coarse adjustment means for re leasing the fine adjustmentmeans and for quickly moving the rest away from the work or .toward itto a point where fine motion required.

Specification of Letters Patent.

Patented Feb. 25, de lt Serial No. 186,004.

Fig. 2 is an enlarged sectional detail of the horizontal adjustments of1, parts being shown in perspective;

Fig. 3 is a section on the line Fig. 2;

Fig. 4: is a top plan view of the quick; acting nut shown in Fig. 2.

In the practice of my invention, 1 have provided a steadying work-holderadapted tobear against and support rotating work,

which is accurately adjustable toward and from the work by means of afine motion mechanism and which may be quickly and roughly positionedwith reference to the work by releasing the fine motion mechanism fromoperative relation thereto and manually or automatically moving the restto the desired location.

As a specific embodiment of one phase of my invention, as applied to thegrinding art, the construction illustrated may be utilized for steadyingwork being ground. however, obvious that similar constructions withinthe scope of my invention may be utilized in other arts for steady reststo support work bein rotatively treated by various methods. fieferringto Fig. 1, the steady rest may comprise a shoe-holder 1O supported byand movable relative to a body or stand 11, fastened to a suitable partof a grinding machine 12. Rigidly fixed between a shoulder 13 on theshoe holder 10 and a clamp 14: bolted to the holder is a work supportingshoe 15, which, in the present form, has two spaced bearing surfaces 16and 1? adapted to engage the work. 18 in any deit is.

low the horizontal diameter of the work oposite the side being round,theother, 17, eneath the work an in the rear of a vertical diameter.

To adjust the position of the bearing block or shoe relative to thework, I provide means for moving the shoe holder both vertically andhorizontally or substantially in the direction of thrust of the workagainst each contact surface onthe steady rest. As illustrated, thestand 11 comprises an L shaped portion 20 having a circumferentialflange 21 on one arm, projecting forwardly and telescoping within area-rwardly extending hollow body I portion 22 on the shoe holder,thereby furnishing an interior space for the holder supportingmechanisnnwhich is protected from the entrance of a material amount ofwater by the overhanging flange 23 of the holder.

One of the steadying work holder supports consists in the presentembodiment of a roller 24, riding on the track or roll bearing plate 25fiXed on the stand 11. The roller 24 is rotatably mounted on a pin 26,

between the two lugs 27 on a swinging arm 28,-which in turn is hinged tolugs 29 on the holder, whereby the latter may be adjusted upwardlyrelative to the track 25.

'Resting on the top curved surface '30 of arm 28 is the head 31 of abolt 32 connected tothe holder and adapted to serve as one support forthe shoe and to furnish a vertical adjustment, as explained below. The

surface 30 may have a radius equal to itsv distance from the center ofpin 26 t-rated. I

The other support for the holder and shoe comprises a substantiallyvertical adjustment link 33 pivotally connected to the lug 34 on thestand and lugs 35 on the shoe holder and permitting backward and forwardmotions of the holder on its roller track. F astened to the same stud36, which attaches link 33 to lugs 35, is another link 37, connectingthe holder 10 with the longias illustudinally movable .bolt 38, which ishori-- .zontally positioned in the stand 11 and serves as part of theadjusting means. A projecting lug 39 on link 33 may be provided toengage the stand 11 and thereby limit the forward motion. of the shoeholder.

In order that the Work holder and its shoe may be quickly moved to adesired position and then. finely adjusted against the work, I haveprovided a special mechanism comprising a partioular,feature of myinvention. In its preferred form, this involves a screw threadedadjustment member connected to the holder and movably held relative tothe stand by a releasable two part clamping nut, which may be rotated tomove the adjustment member and holder with a slow, fine, arxzuratemotion, or which may be longitudinal adjustment, by means of a set screw42 in the arm engaging a long groove 43 in the bolt. Rotatably fastenedto arm 41 is a nut bearing casing 44 having a constricted neck portion45 with an annular flange 46. Two semi-circular pieces in this neckconstitute a thrust collar 47 which is immovably held, relative to thebody 11, by means of a set screw 48, thereby permitting rotative but notlongitudinal motion of the casing 44.

The bolt 38 is longitudinally slidable through the casing 44 and thestand 11, to

cause horizontal motion of the shoe holder,

and is actuated by means of my special twopart clamping nut provided.for that purpose. This nut comprises two separated half-nuts 51 and 52having projecting lugs 53 hinged to ether by means of a pin 54 on eachside of the not, these pihs passing through casing 44 and causing thenut and casing to rotate together and preventing longitudinal movementof the clamping nut. The inner portion of the clamping nut comprises asubstantially conically shaped jaw fitting within the hollow casing 44and having inner threads 56 adapted to engage cooperativelywith thescrew threads 57 on bolt 38. The outer ends of the nut comprise tlaring,flanged, separated portions 58 serving as a handle for turning the nut,or, by pressing them toward each other, for releasing the clamping jawsfrom engagement with the bolt. Suiiicient opening of the nut jaws toprovide clearance between nut and bolt permitted, because of theconically shaped jaws being normally separated considerably from theinner inclosing walls.

As shown, the outer body portion of the clamping nut may be larger indiameter than casin 44 and have an annular flange portion 59 projectingover the casing to aid the interiorof the nut.

Springs (31 within casing 44 serve to hold the jaws 51 and 52 normallyin engagement with the bolt thread. To cassethe bolt and jaws to engageeach other firmly when brought into contact, I prefer to make thethreads of the bolt, buttressed, as illustrated, with a substantiallyvertical shoulder 62 facing outwardly, and the threads of the 'U-shapedmember having a bolt threaded:

thrbugh one arm at one side of the main threaded pertoration forengagement with 'the other arm to draw the arms closer and causefrictional engagement of the threads of nut-'64 and bolt -38. A shoulder66 on the lock nut is adapted to engage a set screw 67 within the hollowflanged outer end of one of the nut portions 51 and thereby limit theinward motion of the bolt.

In the vertical adjustment mechanismgthe casing 44 is similarlyrotatably mounted on the holder 10. and the clamping nut is tastened tothe casing, the downward pull of the weight of the holder on the bolt 32maintaining the holder in a definite relation to the stand, depending onthe relative position of bolt 32 and the clamping nut. To counterbalancethe downward pull due to the weight of the shoe and to insure quick andeasy action in roughly adjusting the steady rest into contact with thework, I may provide the vertical adjustment bolt 32 with a concentrichelical compressed spring 70 between the bolt head 31 and a shoulder 71in a circular groove on the under side of the holder 10. This spring ispreferably strong enough to lift the work holder, so that it may serveaS an automatic means for moving the holder when the clamp nut isreleased. While the other boltadjustment member may be provided with asimilar spring, I find that this may be omitted, as illustrated.

To clamp the steady rest to the work table I may provide the latter withan undercutshoulder 75 engageable by a clamp arm 76.0n the member 77pivoted to the stand 11. The clamp arm is actuated by a link 78connected to a handle 79 pivoted to the stand 11, the link 78 and handlepivots being out of alinement, whereby, as illustrated, upward motion onthe handle releases the clamp and downward motion alines the pivots andlocks the clamp. Obviously, any suitable and desired type of clamp maybentilized for this purpose.

The operation of my device, which is apparent from the foregoingdisclosure, is as follows:

j After the work 18 has been located in grinding relation to thegrinding wheel and the steady rest has been properly positioned oppositethe surface to be ground, the operator may releaseboth half nuts fromenthe nuts handles pressed inwardly, to locate both shoes inapproximately a correct position. In normal use, the steady restisordinarily moved but slight distance to release the work; so that when anew part to be ground has been positioned, it is mere necessary tocompress both clamp nuts, whereupon the lower shoe automatically rises,and traveling along the under front side of the cylindrical surface,draws the rest forward until the other shoe also in contact with thework. Upon releasing the clamp nuts, which resume operative contact withthe threaded bolts because of the action of the spring 61, the nuts maybe individually turned on the bolts to adjust the shoe bearing surfacesin place with fine pi The set or locking nut 64- may brought up andclamped in positio abut- .ther

ting against the stop 6?, whereby in use of the steady rest forduplicate gr r- 3 1g operations, the ad usting nuts he quickly screwedinto correct supporting relation to the work without the necessity forextreme care on the part of the operator. Also a micrometer adjustmentmay be obtained by setting the clamp nut shoulder 66 at a definite anglerelative to the stop 6?,

so that by turning the clamp nut until. the shoulder strikes the stop, apredetermined, fine adjustment of the rest is made. As the grindingoperation proceeds the posi "on of the shoe may be adjusted; if desired..o re move the work, the clamping nuts are released and the shoe holderquickly moved downwardly and horizontally in a single operation. It istherefore seen that a material saving of many seconds or time for eachmovement of the shoe holder is made, whiclrresults in the course of aday in a considerableeconomy of time and an increased output. where sucharticles as crankshafts, requiring but little grinding, are beingtreated.

Having thus described my invention, what I claim and desire to secure byLetters Pat ent is: r

1. In a steady rest, a work holder adapted to engage the surface orrotating work a,

and for then effecting a line precision adjust ment to the requireddegree of pressure to steady the rotating body.

tits

2. In a steady rest, a work holder, a support therefor, fine precisionmechanism for accurately positioning said holder relative to the workand means for releasing said fine precision mechanism from its operativerelation to said holder irrespective of the relative positions of theparts and permitting manual movement of the holder toward the work for aquick, coarse adjustment thereof in any oneofvarious locations relat1veto the work axis, said mechanism being thereafter operable to positionthe holder accurately.

3. In a steady rest for arotatingbody, the combination of a stand, awork-holder carried thereby and adapted to contact with said body, aslow motion device for adjustmg said holder, relative to the stand, and

means for releasingsaid slow motion devicefrom operative relationshipwith the holder and permitting the latter to be moved quickly toward orfrom the work.

4. In a steady rest, a stand adapted to be fixedly positioned relativeto the work to be steadied, a work-holder movably mounted on said stand,an adjusting member connected with the holder and fine motion mechanismsupported by the stand and removably clamped to the adjusting member toposition the holder accurately relative to the work, said mechanismbeing releasable fromoperative relation with the-adjusting member topermit quick relative movement of the parts to substantially the desiredposition, whereupon a fine adjustment may be made by means vof said finemotion mechanism.

5. In a steady rest, a support, a work holder adapted, to engage thesurface of rotating work and means for efiecting a fine adjustment ofthe position of the holder, comprising a threaded rod and a clamping nutmovable relative to each other, one of which connects with the holderand the other with the support, said clamping nut being releasable fromtherod to permit a quick, coarse adjustment of the holder.

6..In a steady rest, the combination of two relatively movable members,one adapted to support work being treated, a threaded adjustment rodrotatably and longitudinally immovable relative to one member, and areleasable, threaded clamping nut engaging said rod and rotativelymovable but longitudinally in'n'novable relative to the other men'rbe'r,whereby said nut may cooperate with said rod and serve as a fine motionmechanism tor moving the worksupporting member or may be releasedtherefromto permit a quickadjustment of the relatively movable parts.

7. In a steady rest, an adjustable workholder adapted to engage work tobe steadied, a stand carrying said holder, a

screw-threaded bolt non rotatably connected with said holder for movingthe same, an internally threaded member rotatably supported by the standand adapted to cooperate with said bolt to move the holder with a finemotion, and means for instantly disengaging said member and boltirrespective of their relative positions to permit rapid relativemovement of these parts.

8. In a steady rest, the combination of a stand, a work-holder, meansfor supporting said holder movably on the stand, a threaded adjustmentmember connected with the holder, means for holding said memberrotatively. but not longitudinally immovable relative to the stand, anda clamping nut rotatably carried by the stand and coiiperativelyengaging the adjustmentmember to move the same with-a fine, accuratemotion, said nut being releasable from said member for a coarseadjustment of the holder.

9. In a steady rest, the combination with. a supporting stand and awork-holder movable relative thereto, of a longitudinally movable butnon-rotative screw threaded adjusting member connected with theworkholder, a screw threaded clamping device adapted to coiiperaterotatively with the adjusting member to move the holder with a fineaccurate mot-ion, means for quickly releasing the threaded parts fromoperative engagement with each other and means for automatically movingsaid holder relative to the stand when the parts are released.

10. In a steady rest, the combination with a stand and a work-holdermovably mounted thereon, of means for adjusting-said holderverticallyrelative to the stand, comprising a rotatively immovablethreaded member supported by the stand, a threaded clamping nutcotiperatively engaging the threaded member and rotatably fastened toand supporting the holder, whereby the latter may have a fine motionadjustment by rotation of the clamping nut, and means for releasing theclamping nut from engagement with the threaded member to permitlongitudinal,

non rotatable relative movement of nut and member for a quick, coarseadjustment of the position of the holder.

11. In a steady rest, a stand, a workholder movably supported thereon, athreaded adjustment member non-rotatably connected with the holder, arotatable clamping nut con'l'prising two threaded halt-nuts hingedtogether, resilient means causing said nut normally to engage saidmember, and means whereby rotation of said nut will move said memberand-holder with a fine motion, said halt-nuts having means, includinghandles, for releasing them from operative engagement with said memberto permit rapid movement of the holder.

12. In a steady rest for supporting rotatholder, said-member and clampnut having ing work, the combination with a stand and buttressed threadsadapted to prevent disena Work holder movable relative thereto, ofgagement ther'e'of due to pressure of the 10 a screw threadedimemberoperatively en- Work. 5 gagin oneof said parts, a releasable and Signedat Worcester, Massachusetts, this rotata 1e clamp nut coiiperating withthe 10th day of August, 1917. other part for adjusting the position ofthe HOWARD W. DUNBAR.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. 0."

